ローラーチェーンの名称とサイズ表記の理解
英国のエンジニア、調達マネージャー、保守担当者が国際的なサプライチェーン規格を理解するための、決定版技術ガイド。
If you have ever tried to order a replacement roller chain for a production line in Birmingham and found yourself staring at codes like 10B-1, 12A-2, or 50H, you already know that the naming system for these components is far from intuitive. Roller chains are among the most widely used power transmission components in British manufacturing — found in everything from food processing conveyors in Leeds to agricultural machinery across the East Midlands — yet their designation standards continue to confuse engineers and buyers alike. The confusion typically stems from the coexistence of two major standards: the British Standard (BS) system and the American National Standards Institute (ANSI) system, each with its own logic, its own numerical sequences, and its own unit of measurement at its core.The Foundation — Pitch as the Primary Identifier
Pitch is the single most important dimension in roller chain nomenclature. It describes the centre-to-centre distance between adjacent pins, and every other dimension of a chain — roller diameter, inner plate width, pin diameter, breaking load — is determined in proportion to it. In the British Standard (BS ISO 606) system, pitch is expressed in sixteenths of an inch, which is then multiplied by a prefix number to give the chain’s designation. So a 10B chain has a pitch of 10 sixteenths of an inch, which is 5/8 inch or 15.875 mm. A 16B chain has a pitch of 16 sixteenths — exactly one inch (25.4 mm). This mathematical relationship makes British chain codes straightforward once the sixteenth-of-an-inch rule is memorised.
In the ANSI/ASME B29.1 system, used predominantly in North America but encountered frequently in global trade, the numbering logic is slightly different. The first one or two digits of the chain number, when divided by 8, give the pitch in inches. An ANSI 40 chain therefore has a pitch of 40/8 = 0.5 inch (12.7 mm). An ANSI 80 chain has a pitch of 80/8 = 1 inch (25.4 mm). The absence of a suffix letter in the base code is itself informative: it indicates a standard ANSI chain, whereas a suffix letter signals something else (heavy series, offset link plate, etc.). Understanding both numbering systems is essential for any UK buyer dealing with machinery imported from North America, Japan, or mainland Europe, where ANSI specifications are routinely mixed with ISO-based designations.
Example: 10B → 10/16 = 0.625 in (15.875 mm)
Example: 40 → 40/8 = 0.5 in (12.7 mm)
Suffix Codes — The Letters After the Number
Once the pitch prefix is clear, the suffix letters and strand-count designations become the second tier of information embedded in a roller chain code. In the British Standard system, the suffix B indicates a metric-pitch BS chain — this distinguishes it from the ANSI numbering family. A chain labelled 16B is unambiguously a British Standard chain with a 1-inch pitch, conforming to BS ISO 606. The suffix R (e.g., 10B-R) sometimes appears in specialist catalogues to denote a roller chain with a large roller diameter variant, though this is less common in mainstream UK industrial supply.
Strand count is encoded by a hyphen and number immediately following the core code. A simplex (single-strand) chain carries no strand suffix in many catalogue conventions, though some suppliers append -1 explicitly. Duplex (two-strand) chains are written with -2 (e.g., 10B-2), and triplex (three-strand) with -3 (e.g., 16B-3). In heavy-duty applications — such as the drive systems found in large-scale industrial presses common in Sheffield’s manufacturing sector — multiple-strand configurations are routinely specified to distribute load rather than moving to a larger pitch chain, which might necessitate a full redesign of sprocket geometry. For ANSI chains, the heavy series is marked with an H suffix (e.g., 60H) indicating thicker plates and a higher static breaking load for the same pitch.
BS versus ANSI — Why Both Standards Matter in UK Industry
- Pitch in sixteenths of an inch (suffix B)
- Inner link width in millimetres for B-series
- Dominant in UK, EU, and Commonwealth markets
- Common sizes: 06B, 08B, 10B, 12B, 16B, 20B, 24B
- Preferred by OEMs in Birmingham, Manchester, Bristol
- Used in most British-manufactured agricultural machinery
- Pitch = number ÷ 8 (in inches)
- Narrower inner width than BS at same pitch
- Widely used in imported US/Japanese machinery
- Common sizes: #25, #35, #40, #50, #60, #80, #100
- H suffix = heavy series with thicker plates
- Encountered in automotive and packaging plant imports
The practical consequence of this dual-standard environment is significant for UK maintenance engineers. A BS 16B chain and an ANSI 80 chain share the same pitch — exactly one inch — but are not interchangeable. The inner plate width, roller diameter, and overall chain width differ, meaning sprockets designed for one standard will not properly engage the other. This distinction becomes critical in facilities like the large food processing plants found across Yorkshire and the East Midlands, where a production stoppage caused by an incompatible replacement chain can mean thousands of pounds in lost output per hour. The rule of thumb taught to apprentice engineers in Birmingham’s manufacturing colleges still applies: match the standard, not just the pitch.
Modern BS ISO 606 has moved to align pitch designations in millimetres for documentation purposes, though the legacy B-suffix numbering persists universally in trade. When dealing with contemporary roller chain catalogues, you will frequently encounter both the B-number designation and the metric pitch value printed side by side — for example, “10B / 15.875 mm pitch.” This dual-labelling reflects the industry’s accommodation of both engineering traditions and makes cross-referencing between British and continental European suppliers considerably more manageable for procurement teams operating across post-Brexit supply chains.
製品の技術的および性能的パラメータ
Comprehensive dimensional and mechanical data for the most widely used BS (ISO 606) and ANSI simplex roller chains. All values are nominal; working loads assume a service factor of 1.0 in clean, well-lubricated conditions.
Working Principle and Core Materials in Roller Chain Construction
A roller chain transmits mechanical power through a sequence of interlocked links where each roller engages a sprocket tooth, rotates freely on its bushing, and disengages cleanly as the chain wraps around the sprocket arc. The rolling contact between roller and tooth minimises sliding friction, which is the primary reason roller chains achieve transmission efficiencies routinely above 97% — a figure that even well-maintained flat belts cannot match at equivalent loads. The chain’s inner link plates are pressed tightly onto the bushings, whilst the outer link plates hold the pins. The pin rotates inside the bushing as the chain articulates around the sprocket, and the bushing itself is what the roller rides upon.
The material selection for each component is a carefully engineered balance. Link plates are typically cut from medium-carbon or alloy steel strip, heat-treated to a core hardness that provides toughness against shock loading while the surface remains machinable. Pins are produced from case-hardened alloy steel and ground to close tolerances — typical pin roundness tolerances in precision-grade chains are held within 0.005 mm. Bushings and rollers are made from low-carbon steel that is carburised and case-hardened, giving a hard outer shell capable of withstanding the rolling/sliding contact with the sprocket tooth and pin surface respectively. The differential hardness between pin and bushing is deliberately engineered to ensure the bushing wears preferentially, since it is the less expensive component to replace in a rebuild scenario. For stainless steel chains — increasingly popular in UK food factories, chemical plants in Teesside, and pharmaceutical facilities in the Midlands — AISI 304 or AISI 316 is used throughout, accepting a lower tensile strength in exchange for substantially improved corrosion resistance.
英国製造業における産業応用シナリオ
Correct size designation knowledge translates directly into correct chain selection for each application environment.
Precision timing chains and transmission drive chains on assembly lines demand exact pitch compliance and low elongation rates. The West Midlands automotive corridor — covering plants from Coventry to Solihull — typically specifies 10B-1 and 12B-2 roller chains for conveyor systems, with ANSI 50 and ANSI 60 used on American-sourced pressing equipment. Precise size designation ensures interoperability during planned maintenance windows where downtime is measured in vehicle units per hour, not minutes.
Combine harvesters, balers, and grain auger systems in Lincolnshire and Cambridgeshire rely extensively on large-pitch BS chains — 16B, 20B, and 24B are standard across British agricultural OEM output. Duplex chains (-2) are common on main drive shafts where high torque is transmitted, while straw-handling conveyors may use specialist attachment chains with bent or extended link plates. The naming code must account for pitch, strand count, and attachment specification simultaneously when ordering replacement parts during the short harvest window.
Abattoirs, dairy processing facilities, and ready-meal production lines across Yorkshire require stainless steel roller chains (SS suffix, AISI 304 or 316) to meet HACCP compliance and withstand repeated washdown cycles. The size designation must include both pitch and the SS specification; substituting a standard carbon steel 08B-1 for an 08B-1-SS due to a misreading of the code carries serious food safety implications. Many modern UK food processing sites have migrated to chains with self-lubricating sintered bushings (ZB suffix) to eliminate external lubrication in food-contact zones entirely.
Rolling mills, coil handling lines, and slag processing equipment in South Yorkshire demand chains at the extreme end of the size range — 24B-3 and larger, or ANSI 160H heavy series — where breaking loads exceed 400 kN and shock resistance is paramount. At these sizes, chain mass itself becomes a factor in dynamic load calculation, making precise weight-per-metre data from the size designation table directly relevant to drive engineering. Sheffield-based maintenance teams typically hold critical spares in the 16B to 24B range due to long lead times on very large pitch chains from European suppliers.
Automated sortation conveyors, pallet movers, and overhead trolley systems at UK distribution hubs along the M1 and M6 corridors use predominantly small-pitch BS chains — 06B-1 and 08B-1 are the workhorse specifications. The volume of chain consumed in a large distribution centre can run to hundreds of metres per maintenance cycle, making accurate size designation critical for bulk ordering accuracy. Rubber-top attachment chains (G suffix) are used in manual-picking zones where product surfaces must be protected during conveying.
A 20B-pitch chain with factory-fitted rubber top plates — ideal for conveyor lines handling fragile or surface-sensitive goods in packaging and light manufacturing. The rubber bonding meets food-grade contact specifications and withstands routine washdown.
Core Technical Advantages of Precision-Grade Roller Chain
Ever Power — Precision Manufacturing and Custom Roller Chain Solutions for UK Industry
Factory capability | Customisation | Supply chain reliability
Ever Power’s manufacturing operation runs across dedicated roller chain production lines equipped with CNC pin and bushing grinding centres, automated plate blanking presses, and continuous chain assembly and tensioning equipment. The result is dimensional consistency that meets or exceeds BS ISO 606 tolerance classes across the entire product range, from the smallest 04B pitch chains up to 48B heavy industrial chains. Every batch undergoes load testing — each completed roller chain is proof-loaded to 50% of its published minimum breaking load before despatch, generating a traceable test record that accompanies the shipment documentation.
For UK buyers, Ever Power’s supply chain infrastructure means genuinely fast turnaround on standard sizes — warehouse stock in the most-used BS and ANSI designations supports ex-stock fulfilment with DDP (Delivered Duty Paid) shipping options direct to UK mainland addresses, eliminating import customs uncertainty from the procurement equation. For engineered or custom specifications, a dedicated project engineering team handles drawing review, prototype production, and first-article inspection before full-production orders are released. Lead times for custom roller chain configurations — including bespoke attachment patterns, extended pitch series, or corrosion-protected finishes outside the standard stainless grade — are agreed contractually and monitored against milestone reporting.
- Any BS / ANSI pitch from 06B to 48B
- Simplex, duplex, triplex strand configurations
- Attachment link patterns: K1, K2, K2F, bent plates
- Stainless (304/316), nickel-plated, zinc finish
- Rubber-top and plastic-top G-series chains
- Sintered self-lubricating bush (ZB) option
- Extended pin, carrier attachment, tab configurations
- Shot-peened heavy-duty plate variants
- BS ISO 606 / ANSI B29.1 dimensional compliance
- 100% proof load test on production batches
- Material traceability from steel mill to despatch
- ISO 9001 quality management framework
- DDP shipping — UK mainland, no import duty surprise
Discuss your roller chain specification with our engineering team
The 24B-G1 occupies the intersection between the large-pitch drive chain world and the conveying chain market. With a 38.1 mm pitch providing substantial breaking load capacity and the factory-bonded rubber top plate offering non-slip, product-safe carrying surfaces, this variant is particularly well-suited to inclined conveyor applications in bottling plants, tyre manufacturing, and general automotive parts handling — industries with a strong presence in the Midlands and North of England. The G1 designation specifies a single rubber pad per link, centred above the outer link plate, providing smooth contact without aggressive grip that could mark finished surfaces.
| ピッチ | 38.1 mm |
| 標準 | BS ISO 606 |
| 最小破断荷重 | 160 kN |
| トッププレート | ゴム、接着 |
| 材料 | Alloy steel |
| 重さ | 約7.1 kg/m |
顧客成功事例：ウェイクフィールド・プレシジョン・コンポーネンツ社（ウェストヨークシャー）
ウェイクフィールド・プレシジョン・コンポーネンツ社は、ウェイクフィールドで中規模のCNC加工部品工場を運営しており、ヨークシャーの自動車および油圧機器業界に旋削加工およびフライス加工部品を委託供給しています。同社のツインスピンドル旋盤とマシニングセンターは、仕掛品ビンを積載ステーション間で循環させるカスタムオーバーヘッドコンベアシステムで接続されています。このシステムは、2009年に10B-2デュプレックスローラーチェーンと戻り経路の08B-1シンプレックスセクションを組み合わせて設置されました。2024年までに、元のチェーンは45,000時間以上の稼働時間を蓄積し、最も負荷のかかるセクションでは伸びが2.8%に近づいており、推奨交換しきい値である2%をはるかに超えていました。
エンジニアリングマネージャーは、以前地元の販売代理店を通じて交換用チェーンを調達していましたが、ブレグジット後のサプライチェーンの混乱によりヨーロッパからのチェーン輸入に影響が出ているため、10B-2仕様の英国在庫のリードタイムが6～8週間と長くなっていることがわかりました。シェフィールドの製造ネットワークの同僚が、Ever Powerに直接問い合わせることを勧めました。既存のチェーンの摩耗したリンクプレートの図面を提出し、同等以上の性能を要求したところ、Ever Powerのエンジニアリングチームは、重要なセクションをショットピーニング加工されたリンクプレートを備えた高硬度の10B-2にアップグレードすることで、ほぼ同じ単価で、施設の特定の負荷プロファイルの下で推定35～40%長い耐用年数を実現できることがわかりました。
180メートルの10B-2と95メートルの08B-1を含む最初の注文は、DDP航空海上複合貨物輸送により18営業日以内にウェイクフィールドに納品され、完全な材料証明書とバッチテスト記録が添付されました。設置後、施設のメンテナンス間隔の追跡では、最初の8,000時間の稼働で0.4%を超える測定可能な延長は見られず、これは大幅な性能向上であり、計画メンテナンス停止期間を年間から28ヶ月サイクルに延長し、サイクルあたり計画ダウンタイムコストを約12,000ポンド節約しました。
ウェイクフィールド、ウェスト・ヨークシャー
10B-2 + 08B-1
全長275メートル
18営業日
自転車1台あたり約12,000ポンド
「エバーパワー社から供給されたショットピーニング加工済みの10B-2チェーンは、伸び耐性の点で当社の期待をはるかに上回りました。8,000時間使用していますが、交換時期の閾値をはるかに下回っており、以前のチェーンと比べて劇的に改善されています。バッチテスト証明書は、当社の品質管理チームが必要としていたトレーサビリティ文書をまさに提供してくれました。」
「最も印象的だったのは、Ever Power社のエンジニアリングチームが実際に当社の負荷データを読み込み、単に同等品を供給するのではなく、より高性能なプレート仕様を推奨してくれたことです。このような積極的な技術対応はサプライチェーンでは稀で、ほとんどの販売代理店は注文番号を処理するだけです。ウェイクフィールドへの18日間のDDP配送は、取引量を考えると素晴らしいものでした。」
「その後、補助機器用にBS規格の小型サイズ（06B-1と08B-1）を3回追加発注しましたが、ロット間の品質の一貫性はメンテナンスプログラムに必要なレベルを完璧に満たしています。新しい部品を取り付ける際にスプロケットの噛み合い調整が一切不要だったことから、製造公差が確実に守られていることが分かります。エバーパワー社は今や当社の主要チェーンサプライヤーです。」
よくある質問 — ローラーチェーンのサイズと英国における供給
英国のエンジニアや購買担当者がローラーチェーンの選定、調達、仕様に関して最もよく尋ねる質問への回答。
Ever Power社は、BS ISO 606およびANSI規格のローラーチェーンを標準仕様およびカスタム仕様で提供しており、英国本土へのDDP配送に対応しています。仕様書をご提出いただければ、当日中に技術レビューを実施いたします。
